1. Field of the Invention
The present invention relates to an automatic piston-installation apparatus for inserting a piston to which a connecting rod is pre-attached into an engine cylinder block and automatically installing the piston to a crankshaft. More specifically, the present invention relates to an automatic piston installation apparatus for automatically installing a piston in a multiple cylinder engine in which cylinder bores are arranged in a line or in the shape of a “V”.
2. Description of the Related Art
An apparatus disclosed in Japanese Unexamined Patent Publication No. H2000-198030 is known as an example of an apparatus for inserting a piston into an engine cylinder block. In the piston insertion apparatus disclosed in this publication, an inline four-cylinder type engine is conveyed by a conveying line, and is positioned at a predetermined position, and, thereafter, a piston is guided to a cylinder bore by use of a guide cylinder while being pushed with a pushing member from above.
This piston insertion apparatus is designed so that the piston can be smoothly inserted while positioning both the piston and the cylinder bore by use of the guide cylinder when the piston is inserted into the cylinder bore.
Additionally, the engine to be used here is an inline-type multiple cylinder engine in which cylinder bores are arranged in a line and which is conveyed by the conveying line while being directed upward. In this engine, a cylinder block is positioned merely by stopping it in the course of a conveyance, and no consideration is given to piston insertion in an engine in which the penetrating directions of cylinder bores differ from each other like a V-type multiple cylinder engine that has cylinder bores arranged in the shape of a “V”.
The conventional apparatus is, as described above, designed to automatically perform only the piston-inserting operation, and not designed to automatically perform all of the installing operations of the piston and the connecting rod after completion of the insertion, including the connection of the connecting rod thereto.
Therefore, if an attempt is made to automatically perform all procedures until the piston is attached to a crankshaft (crankpin) after the piston is inserted, the piston can be inserted merely by stopping and positioning the cylinder block conveyed by the conveying line at a predetermined position, but it is difficult to fix the connecting rod thereto from below because the conveying line is positioned at a lower place.
Additionally, the piston can be inserted into the cylinder block of the inline-type engine, whereas the piston can not be easily inserted into the cylinder block of the V-type engine.
Still additionally, since a connecting-rod cap used to pinch the crankpin is needed for connecting-rod connection, attention must be paid to a method for supplying the connecting-rod cap.
Therefore, in engines used for automatic piston installation, such as the inline-type engine, the V-type engine, and various engines that differ in bore diameter, in bore pitch, or in stroke, it is difficult to insert the piston into all cylinder bores, then fix the connecting-rod cap, and perform piston installation merely by stopping the cylinder block conveyed by the conveying line and positioning it on the conveying line.
Additionally, in a case where the piston is installed by positioning the cylinder block on the conveying line, the piston can be inserted from above in a vertical direction, but the connecting-rod cap can not be fastened from below in the vertical direction. Therefore, the connecting-rod cap must be fastened after the direction of the cylinder block is changed sideward, for example. This change in direction of the cylinder block brings about an increase in the number of installation steps, difficulty in shortening the installation time, and a concern that the piston will be deviated from a correct position during the change in direction of the cylinder block. Therefore, it is extremely difficult to install all pistons with a high degree of accuracy.
The present invention has been made in consideration of the aforementioned circumstances. It is therefore an object of the present invention to provide an automatic piston installation apparatus capable of automatically performing all installing operations ranging from piston insertion to connecting-rod connection into an engine cylinder block in a working area apart from a conveying line and capable of automatically installing pistons not only in single cylinder engines but also in multiple cylinder engines such as inline-type and V-type engines.